MIT researchers discovered that by wrapping the filament of an incandescent bulb with a “photonic crystal,” they could “recycle” the energy that was typically lost as heat to create more light.

The new technique “makes a dramatic difference in how efficiently the system converts electricity into light,” said the research team led by MIT professors Marin Soljačić, John Joannopoulos and Gang Chen.

Their results were published online in the January edition of the journal Nature Nanotechnology.

“The heat just keeps bouncing back in toward the filament until it finally ends up as visible light,” MIT post-doctoral researcher Ognjen Ilic explained. “It reduces the energy that would otherwise be wasted.”